Coke and gas apparatus and process



26h25@ KSQ Alk Aug- 5, 1929- H. KoPPERs c'oxE AND GAs APPARATUS' AND PROCESS Filed July '7. 1921 Patented Aug. 6, 1929.

UNITEDy STATES PATENT OFFICE.y

HEINRICH KOPPEBS, 0F ESSEN-EUHR, GERMANY, SSIGNOB T0 THE HOPPEBVBDE- VELOPMENT CORPORATION, OF PITTSBURGH, `PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

com AND GAs APPARATUS AND rnocnss.

Application tiled; July 7, 1921, Serial No. 483,048, and in Austria September 5, 1919.

(GRANTED UNDER THE PROVISIONS' 0F TH ACT 0F HARCH 3, 1921, 41 STAT. L.,v1313.)

The invention relates to apparatus for the utilization of coal by the conversion of the same into gas, or gas and coke, with the principal object of combining the operations of a coaldistillinv means and a water gas generator, while keeping each within its proper limits of operation so that each part of the apparatus may be fully controlled to the best advantage; for the ultimate production, with as complete utilization of the coal as possible and great economy, of an enriched water gas; this being mainly effected by conducting the hot blast gas of the gas generator`through a charge of coke 1n addition to the coke in the usual water gas generator (preferably in the upper part of the gas generator) and then burning said hotv blast gas in the coal distillation plant, op-

erated with regenerative `heat recovery as y exemplified in my Patent 818033.

The progressive development on the one hand, and economic conditions on the other, have had a tendency to render the manufacture of gas from coal ever more perfect, in which connection incandescent gas mantles were in general adopted so that it was no longer necessary to work towards increased production of a gas of great illuminating power, but merely a certain heating value had to be taken into account; for this a maximum heating value in European practice of about 393.4 to 505.8 B. t. u. per cubic foot would be sufficient. Attempts have been made to solve the problem thus presented b using water gas generators which smol er or distill off gas at the top and gasify at the bottom and which are blasted with air in alternation therewith. In this manner water gas is to be enerated in an intermittent manner which, y virtue of its contained or body heat, is able to distill the coal and thus produce an enriched water gas.

A fundamental drawback of all these processes isthe fact that the gas distilling and the gasifying processes partly overlap each other and because there also exists an undesirable dependence on the other steps of sarily put up. with which were caused by the inter-dependence ofthe different stages of distillation, gasification and manufacture of the water gas. This makes itself felt particularly in connection with coke in that, as is well know, very yhigh requirements are demanded of a good cokefor water gas generators with reference to its hardness, its structure, the uniform size of the pieces and the combustibility, while the coke made in such smoldering or distilling gas producers is inferior in character and does not afford a uniform gas penetration. The conditions suitable for the formation of the coke are fundamentally so unfavorable in such smoldering gas producers that a satisfactory remedy cannotbe expected, even of improvements made in these' arrangements.

Another restriction in connection with this process is created by the fact that it is impossible to control the quantity proportions in the desired manner, since the'nature of the process, as a whole, results in very different dependent factors in this respect. Thus, it is for instance very diflicult to withdraw from the process a part of the coke, as may appear desirable under certain circumstances, and on the contrary every effort must be made to gasify the entire quantity of the coke.

The invention copes with the same task, of

as perfect and economical as possible a utili-` zation of the coal, by proceeding from the idea that the various stages, of the gas expulsion or distillation with production of suitable coke, the gasification, and the manufacture of water gas, must be kept strictly separate, so that there will be clearly defined limits between them. In this manner it Will then not only be possible to fully control the individual processes or steps by themselves and thus to bring them to the highest state of perfection, but it will also be feasible tosystematically re late the mixing proportions between the Listillation gas and the water gas, while moreover there `will be every facility fory withdrawing from the processand otherwise utilizing as a special product a partial quantity of the coke obtained by the gas distillation; and this is done in such a waythat the coal has its gas expelled or is distilled in retorts or distilling chambers in order to obtain, first, a high grade distillation gas and, secondly, a coke which will meet all the requirements of the water gas process. In a separate water gas generator a part of the coke so produced is converted into Water gas by being blown hot with air at one stage,the actual manufacture of Water gas'occurring in the second stage by passing steam over the coke. The water gas obtained in this manner is used for diluting the distillation gas, While the process is turned into a cyclic process by using the gases obtained in air blasting, for heating the distilling or coking retort ovens, which is rendered possible by the use of heat recovery by means of regenerators.

This use of a regenerative heat recovery in the distilling plant proper is of the utmost importance in connection with the process as a whole, because only this manner, (i. e., passing the hot blast gas through the regenerators of the distilling or coking retort ovens to preheat them before they enterthe flame dues), is it possible to enable the hot blasty gases of the water gas generator which are inferior in themselves, to carry out the heating of the distilling chambers; at any rate, the heat recovery heretofore customary for distilling ovens with two chamber-heaters, or so-called recuperators, is of such low efficiency, that the idea of a proper utilization of the hot blast gases would practically forbid itself. Thus, the proposition which has already suggested itself of rusing the hot blast gases of a water gas generator for heating retort ovens, 'was found impracticable. Neither did the idea of blowing into the water gas generator steam together with the air during this time (of making generator gases proper) bring about any relief, and, in fact this again and in the same manner as set forth in theintroduction, by way of reaction caused an impairment of the stage of production of true water gas. Only by resorting to regenerative heat recovery has this idea of utilizing the hot blast gases of a water gas generator been rendered possible in itself and thus the opportunit been afforded for the embodiment of t e process as a whole, as a closed cyclic process.

The moment such an economically and practically satisfactory utilization of the hot blast gases is obtained, the conditions for this stage of the water gas generation, and the process itself, are completely changed; heretofore, the hot blast gases always had to be looked upon essentially as a loss because they were sent into the open or were only utilized With small economy; for that reason every effort was made to keep the heat value of these hot blast gases as low as possible in order torestrict the direct the opposite result, that of producing a comparatively high grade hot blast gas, is realized. According to a further evolution of the invention, the hot blast stage of the water gas generator is systematically developed by producing a high grade hot blast gas in the first place, while the conditions for the stage of the water gas generation proper, not only fail to be rendered poorer, but on the contrary, are improved thereby.

By directly conducting the het blast gases produced in a water gas generator of the customary construction and dimensions, through a chamber charged with coke, both a physical and a chemical action is obtained; the coke filling on the one hand ,takes away from the hot blast gas its sensible heat, so that it is taken in cooled condition tothe regenerators of the distilling chambers proper; and due to the heat economy of the regenerators of such distilling chambers, a more than sufficient heat surplus is available there for the'pre-heating of the gas. This intermediate cooling of the hot blast gases also has the practical advantage that they can be easily cleaned or purified in the cold condition and especially be deprived of dust, while such a cleaning could not be carried out in the warm condition. The chemical action makes itself felt by the fact that the hot blast gases containing considerable carbonio acid, are enriched by the conversionpof the carbonio acid into carbon monoxide when they pass over the additional body of incandescent coke, whereby the sensible heat is changed into latent heat which can be released at another oint. In order that this coke charge may a Ways be enabled again to yield its sensible heat to the hot blast gases, it is cooled by steam from time to time, the latter being used immediately during the water gas manufacture proper. Here again two effects are also obtained, on the one hand that of bringing the additional coke column back into the requisite initial condition, and, on the other hand, a correspondingly higher pre-heating ofthe steam which is of the utmost importance, as regards quality and quantity, for the water gas manufacturing stage.

If the charge of coke in the water lgas generator and this additional coke column are combined in a single shaft, a natural removal of this additional coke charge, into the shaft of the water gas generator, is obtained in the first place, in which connection the heat with which the coke is charged is suitably utilized. Furthermore, the pressure at the bottom of the water gasgenerator shaft is increased thereby which is important in case the water gas generator Works with tapping -oif of liquid slag; in this manner, the immersion of the glowing carbon into the slag accumulating at the bottom of the water gas generator is then forcibly brought about so that the heavy metal oxides are reduced and. a hot liquid metal layer is formed between the hearth and the slag which prevents in the most effective manner,the otherwise easily possible freezing-in or clinkering of such a water gas generator with slag.

In orderl to make the invention more clearly understood I have shown in the accompanying drawing means for carrying it into practical effect, without limiting the invention to the articular embodiment which is used for il ustration and explanation. In said drawing the figure is an elevation, partly in section, of an apparatus embodying the invention.

The coal distilling retort chamber 10 is provided with the regenerators 11 and 12 which alternately serve as air or gas preheaters and waste heat storers. The gas distilled ofl` in the retort 10 passes through the riser pipes 13 into the collecting main 14 and from here through conduit 15 into the gas holder 16 for storage purposes. The waste heat goes to the chimney through the regenerators or heater 11 or 12 which is temporarily connected as a waste heat storer. Such coal distilling retort chambers 10 are usually constructed and operated in accordance with the disclosure in my prior Letters Patent 818,033, in which the retort chambers are enclosed along each side by heating Walls constituted of individual vertical flame flues, such individual flame flues being communicably connected with either a source of coke oven gas that is not preheated or with producer gas that is preheated before entering the flame flues by regenerators arranged below and parallel with the retort chambers and heating walls. Such regenerators serving when operating for inflow to preheat such roducer gas and also the air which is required to support combustion of either the coke oven gas or producer gas in the flues. Such regenerators when operating foroutilow serve to absorb the waste heat from' the outflowing Waste gases resulting from such combustion in the flame ilues. In coking retort oven construction embodying regenerators which are communicably connected directly with the individual flame flues, the preheatin of the air and producer gas very effective y produces the intense flame required to transmit heat through the heating walls to the coal charge in the adjoining retort chamber. Preheated air is introduced into the chamber 19.

of the water gas generator from the air coni duit 20 in case the slag is to be withdrawn in liquid condition, it then being possible to take the latter from the tapping hole 21. The water gas mixture resulting from the hot blast of air into the lower part of the gas generator which lower part is equivalent to the height of a standard water gas generator putation.

flows through the upper shaftv part, is enriched in carbon monoxide by reduction of carbon dioxide in passing through the additional body of coke in said upper part 31 above line 32 audits surplus passes through conduit 22 into the gas holder 23. That portion of the hot blast gas which is to be burned in the distilling plant goes through the conduit 24 to the distributing pipes 25 and 26 in thc distilling plant to enter one or the other of the regenerator chambers 11, 12 which serves as a gas heater. The greater or smaller part of the coke obtained from the chamber 10 may be brought to the water gas generator, there to be charged through opening27. f For" the purpose of operating the shaft 19 as a water gas generator, steam is introduced through the conduit 28 and pre-heated in the upper part of the shaft, subsequently to be decomposed in the lower shaft part into water gas which is withdrawn through the connection 29 into the conduit 3() which leads to the gas holder 31. From this receptacle 31, a connection conduit 32 again goes back into the illuminating gas holder 16, in which the mixed gas finally used is thus formed. From the conduit 30, furthermore a pipe 33 branches off by means of which, according to the degree of opening of the valve 34, an admixture of water gas to the hot blast gas in conduit 24 can be effected, which latter likewise can be con.- nected or disconnected by means of a valve 36. Connected with the conduit 24 is the gas receptacle 35 as a compensating receptacle.

With this plant the cyclic process described is to be carried out, in performing which 'it is possible, first of all to make it the final aim that the hot blast gas corre- .sponding to the quantity of Water gas necessary, be sufficient to carry out the distillation in the retorts 10. In this procedure one is bound to a maximum heating value, as shown by the following exemplifying com If for any reasons, however, a higher grade of mixed gas is to be furnished, lwhereby the quantity of hot blast gas supplied for heating the distilling plant would become too small, the mixture, by means of the water gas producer, is reinforced to such an extent that a corresponding quantity of hot blast gas and water gas is produced as an additional source of heating fuel for the distilling plant. Since the Water gas, in comparison with the hot blast gas, must be considered a rich gas, it can bev fed separatel through the conduits 33, 24 if the distilling plant is embodied as a compound oven, that is to say, with selective heating by rich gas or poor gas. Since in contradistinction to the distilling gas, the water gas does not contain any hydrocarbon which might be decomposed in the heat recovery plant in connection with the heating, it can be taken through the regenerators Without any danger. A

'Efemplifg/z'ng computation.

One ton of good coal furnishes 360 cubic meters of distilled gas with the heating value of 606.96 B. t. u. per cubic `foot. For distilling oli the gas, one ton of coal requires from 78680 to 80928 B. t. u. and Jfurnishes 660 kilos of good coke. It 1.697 kilos of carbon are gasified in the Water gas generator 3.7 cubic meters of hot blast gas (417.566 B. t. u.) and 2.6 cubic meters of water gas (818.272 B. t. 11.), with atotal heating value of 1235.838 B. t. u., are available. ln order to reduce the heating value of one cubic meter of illuminating gas from 606.96 B. t. u.

to 436.012 B. t. u., illuminating gas and water gas must be mixed4 in the proportion of 1 to 1.4. One ton of pure coal yields 360 cubic meters of illuminating gas, which must. be mixed with 504 cubic meters of water gas to yield 864 cubic meters of mixed gas. For

y manufacturing the Water gas, pure coke is required as follows 1597 5042330 kilos pure coke Which 2.06 results in 330 37=719 cubic meters hot blast 1.697 gases and 81141.56 B. t. u.

Since one ton of coal requires from 78680 to 80928 B. t. u. for the extraction oi its ill'uminating gas, the hot blast gas mixture corresponding to the water gas, is sufiicient in this case to degasify the said quantity of coal. Ot' the 660 kilos of pure coke remaining from the degasiication of the coal; 330 kilos are consumed in the water gas producer and 300 kilos are available for utilirationl otherwise. lf, however, the heating value of the illuminating gas is to be reduced to only 509.734 B. t. u. by the addition ot' Water gas, the 360 cubic meters of illuminating gas resulting from one t0n of pure coal must be diluted with 180 cubic meters of Water gas. Fonproducing the Water gas and this results in 118 3.7*257 cubic meters hot blast which 1.697 give 29224 B. t. u.

= 118 kilos pure coke are required 1235.838 B. t. u. in the form of water gas and hot blast gas, it is still necessary to gasify 51704 B. t. u. 1.697 1235.838 B. t. u.

The quantity of coke to be gasified in the water gas generator, therefore, comes to (118+71=) 189 kilos and of the 660 kilos of coke 471 kilos are available for further utilization.

What is claimed is- 1. An apparatus for conversion of coa-l into gas or gas and coke, comprising, in com bination: a coking retort oven, means for heating said oven by combustion of gas in ilues; regenerators therefor; a Water gas generator; means -for charging said generator with coke; means for injecting steam into said water gas generator; means for providing a hot blast into the lower portion of said generator; means for combining the gases distilled in the coke oven with the water gas from the water gas generator; means for conducting the hot blast gases of the water gas generator to the generators and Huss' or' the coking retort oven.

2. An apparatus Jfor conversion of coal into gas or gas and coke, comprising in combination; a cokng retort oven, means for heating said oven by combustion of gas in iiues; regenerators therefor; a Water gas generator; means for charging said generator with coke; means for injecting steam into said Water gas generator; means for providing a hot blast into the lower portion of said generator; means for combining the gases distilled in the coke oven With the water gas from the gas generator; means for purifying the hot blast gases from the pro- =71 kilos of coke.

ducer; means for mixing a portion of 'thel wat-er gas with the hot blast gas; means or conducting said mixed Water gas and hot blast gas of the Water gas generator to the iiues of the coking retort oven.

3. A process for utilizing coal by conversion of the same into gas and coke, consisting in dstilling illuminating gas from a body 'oi coal in a coking retort oven, and leaving a residue ocoke, producing a het blast gas and a Water gas b the aid of said coke and preheated air an steam, heating said hot blast gas by the aid of the Waste heat from said .distillation and then burning it to produce the distilling heat, collecting the 1lluminating gas and the Water gas and mixing .the same, and from time to time mixin a portion of said water gas with said lot blast gas for burning to heat and distill said coal.

4. A process for utilizing coal by conversion of the same into gas and coke, consisting in distilling illuminating gas from a body of coal in a coking retort oven, producing a hot blast gas and a Water gas by the aid of coke and preheated air and steam;

heating said hot blast gas by the aid of the the aid of coke and preheated air and steam, waste heat from said distillation, and then converting the Carbonia acid of. the lxot blast 10 burning it to produce the distilling heat. gas into carbon monoxide by passing it 5. A process for utilizing coal by Converthrough abody of eolie at a glowing heat, 5 Sion 0f the Same int() gas and Coke7 C011-, llting SllCl llO bllS) gLS by the ald 0f llll sisting in dstilling illuminating gas from WMU? he@ from Sad distultloll und then a, @jf-(503,1 in a, Coking retort Oven Pro; bullllng 1t t0 pl'OdllCe the (llilllllng heat. ducing a hot blast gas and a Water gas by HEINRICH KOPPERS.

CERTIFICATE GF CCRRECTION.

Patent No. 1,723, 280. Granted August 6, 1929, to

HEINRICH KOPPERS.

1t is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as folows: Page 4, line 65, for "1,697" read "1.697", and line 90, claim 1, for the word "generators" read "regenerators"; and that the said Letters Patent should be read with these corrections therein that the same may conform t0 the record of the case in the Patent Office.

Signed and sealed this 29th day of October, A. D. 1929.

M. J. Moore,

(Seal) Acting Commissioner of Patents. 

